Electric paper reading system

ABSTRACT

Objects of the present invention are to facilitate filling out by hand an electronic paper and to realize digitization of contents with which the electronic paper is filled out by hand with a simple structure. A read image is obtained by optically reading a reading-object of the electronic paper. Based on the document information written on the electronic paper and writing-conditions during document writing, which are represented by the document information, a display image of the document in accordance with the read image information is formed. A written image is separated and extracted by converting a density only of pixels among the respective pixels of the read image, whose densities vary in accordance with the document writing and which correspond to a portion, to which ink of a pen for the handwriting is not adhered.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese PatentApplication No. 2003-18284, the disclosure of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic paper reading device, anelectronic paper reading system, and an electronic paper reading method.More particularly, the present invention relates to an electronic paperreading device, an electronic paper reading system, and an electronicpaper reading method for reading contents, which have been filled outonto electronic paper by hand.

2. Description of the Related Art

In recent years, attention has been paid to electronic paper (alsocalled “digital paper”) as anew recording media. Electronic paper hascharacteristics such that an arbitrary image (which could be an image ofcharacters) can be recorded thereon, and an image, which has beenrecorded once thereon, can be rewritten. It is hoped that electronicpaper will even replace paper as a recording medium. Paper hascharacteristics such that, even after an image has been once recorded onthe paper, characters or the like can be additionally filled out by handthereon, by using writing-implements such as pencils or ball-point pens.Accordingly, in order for electronic paper to be used as a medium thatreplaces paper, the electronic paper must, like paper, enable charactersor graphics to be filled out by hand on electronic paper on which animage has already been recorded. Further, the ability to reuse a displayor the like of contents, which have been filled out by hand, as an imageon the electronic paper, by digitizing the contents, which have beenfilled out by hand, is desired.

Techniques for digitizing contents, which are filled out on electronicpaper by hand, have conventionally been proposed. For example, JapanesePatent Application Laid-Open No. 2000-112646 discloses aninformation-processing device which, if an image (including characters)is written/inputted, using an electromagnetic/heat-generating pen, ontoelectronic paper which is fixed on an electromagnetic inductivedigitizer (tablet) digitizes contents which has been written on theelectronic paper by the electromagnetic inductive digitizer, associatesinformation, which was obtained by digitization, with ID information foridentifying respective documents, and stores the associated informationtherein.

However, in the technique described in JP-A No. 2000-112646, in order toenable an electronic paper to be filled out by hand and the contentswith which the electronic paper is filled out by hand to be digitized,it becomes necessary to use special devices such as the electromagneticinductive digitizer, and the electromagnetic/heat-generating pen whichradiates an electromagnetic wave and generates heat during thefilling-out by hand of contents on electronic paper. Further, ifelectronic paper is filled out by hand, it is also necessary to fix theelectronic paper at a predetermined position on the digitizer thusmaking it inconvenient to use the electronic paper. Moreover, since theelectromagnetic/heat-generating pen is a power-consuming device, it mustbe used while paying constant attention to a remaining amount of abattery in order to prevent writing in-ability due to battery run-down.

SUMMARY OF THE INVENTION

In view of the aforementioned facts, an object of the present inventionis to obtain an electronic paper reading device in which filling-out byhand on an electronic paper can be performed easily and digitization ofcontents with which the electronic paper filled out is by hand can berealized with a simple structure.

In order to attain the aforementioned object, a first aspect of thepresent invention is an electronic paper reading device comprising areading component for optically reading an electronic paper which isfilled out by hand, in a state in which a first image which has beenrecorded on the electronic paper in advance, is being displayed, arecognition component for recognizing the first image, and an extractingcomponent for extracting image data of a second image that representscontents with which the electronic paper is filled out by hand, based ona result of the recognition of the first image by the recognitioncomponent, from a result of the reading by the reading component.

In accordance with the first aspect of the present invention, anelectronic paper which is filled out by hand is optically read by thereading component in a state in which a first image which has beenrecorded in advance on the electronic paper is displayed. Thus, in thefirst aspect of the present invention, the electronic paper is opticallyread, whereby the contents with which the electronic paper is filled outby hand is digitized. Therefore, when the electronic paper is filled outby hand, it is possible to use a tool which alters opticalcharacteristics (such as a light reflectance and the like) at a portionof the electronic paper which is filled out by hand, for example, a penwhich is highly in general use and structured such that a medium isfilled out by being deposited with ink. Accordingly, use of a specialdevice such as an electro-magnetic/heat-generating pen becomesunnecessary.

By optically reading the electronic paper, the timing when contents withwhich the electronic paper is filled out by hand are read is not limitedto the timing at which the electronic paper is filled out as in the casein which the electronic paper is read by a digitizer, and the contentscan be read after the filling-out by hand on the electronic paper hasbeen completed. Accordingly, during the filling-out by hand on theelectronic paper, fixing of the electronic paper at a predeterminedposition of the digitizer is not required. Consequently, the filling-outby hand on the electronic paper can be facilitated.

The reading component according to the first aspect of the presentinvention reads the electronic paper on which the first image hasalready been recorded and which is further filled out by hand.Therefore, the reading result by the reading component represents anoverlapped image of the contents with which the electronic paper isfilled out by hand and the first image. Accordingly, in the first aspectof the present invention, the recognition component recognizes the firstimage that is recorded on the electronic paper, and the extractingcomponent extracts image data of a second image that represents contentswith which the electronic paper is filled out by hand, based on therecognizing result of the first image by the recognition component andthe reading result due to the reading component.

Since the reading component according to the first aspect of the presentinvention can use a general reading component such as a scanner, in thefirst aspect of the present invention, use of a special device such as adigitizer is not necessary in order to digitize contents with which theelectronic paper is filled out by hand. Accordingly, in accordance withthe first aspect of the present invention, the filling-out by hand on anelectronic paper is facilitated and digitization of contents with whichthe electronic paper is filled out by hand can be realized with a simplestructure.

In the first aspect of the present invention, in extracting the imagedata of the second image, for example, by the recognition componentrecognizing the first image by obtaining the image data of the firstimage and by the extracting component estimating the first image inaccordance with the reading result by the reading component based on theimage data obtained by the recognition component, and then removing theestimated first image from the image represented by the reading result.In estimating the first image, when the first image is recorded on theelectronic paper, if a processing such as a scaling of the first imageor an adjustment of a recording position of the first image is carriedout, a processing for estimating the first image which is recorded onthe electronic paper based on the original image data of the first imageis also included. Such processings can be performed based on informationthat indicates the way in which the first image is recorded on theelectronic paper. Accordingly, the second image which representscontents with which the electronic paper is filled out by hand can beobtained with high accuracy by estimating the first image in accordancewith the reading result and removing the first image that is estimatedbased on the image represented by the reading result.

It is preferable that identification information for identifying imagedata of the first image or a storage location at which the image data isstored is recorded on the electronic paper (for example, in an aspect inwhich image data is stored in a predetermined storage medium (e.g.,storage medium which is connected to a server), information or the likewhich is associated with information that indicates a storage address orimage data). The information can be optically recorded on the electronicpaper in a formation of one or two-dimensional barcode or can berecorded on an information recording section such as an IC chip which ismounted on the electronic paper.

If the image data or the identification information is recorded on theelectronic paper, the recognition component can be structured, forexample, such that the recognition component obtains image data byreading the image data from the electronic paper or identifies a storagelocation of the image data based on the identification information thatis read from the electronic paper, whereby image data can be obtainedfrom the identified storage location.

The removal of the estimated first image from the image represented bythe reading result can be realized by converting a density of pixelscorresponding to the estimated first image, among respective pixels ofthe image represented by the reading result, to a density of theelectronic paper in the state in which no image is recorded thereon.However, among the respective pixels of the image represented by thereading result, if a density of the entire pixels corresponding to thefirst image is simply converted, contents with which the electronicpaper is filled out by hand disappear at the overlapped portion of thecontents with which the electronic paper is filled out by hand of thesecond image which is extracted by removing the first image which isestimated in accordance with the image represented by the reading resultand the first image.

By considering the above-description, it is preferable to remove theestimated image from the image represented by the reading result suchthat, among the respective pixels of the image represented by thereading result, a density of the pixels which correspond to theestimated first image and whose density difference from the pixels whichcorrespond to the estimated first image is less than a predeterminedvalue or less or a density of the pixels within a range of density whichis defined based on the estimated first image is converted to a densityof the electronic paper on which image is not recorded thereon.Therefore, the pixels that correspond to the overlapped portion of thecontents with which the electronic paper is filled out by hand and thefirst image are excluded from target pixels to be converted.Accordingly, when the second image is extracted by removing the firstimage from the image represented by the reading result, the occurrenceof disappearance of the contents with which the electronic paper isfilled out by hand from the extracted second image can be avoided.

An electronic paper reading device according to a second aspect of thepresent invention comprises a delete control component for deleting adisplay of a first image from an electronic paper which is filled out byhand in a state in which a first image which has been recorded on theelectronic paper in advance, is being displayed, and a reading componentfor obtaining image data of a second image representing contents, withwhich the electronic paper is filled out by hand, by optically readingthe electronic paper from which the display of the first image has beendeleted by the delete control component.

In accordance with the second aspect of the present invention, thedisplay of the first image is deleted by the delete control componentfrom the electronic paper which is filled out by hand in the state inwhich the first image which has been recorded in advance on theelectronic paper is displayed. Accordingly, the electronic paper is inthe state of displaying only the contents with which the electronicpaper is filled out by hand. Further, in order to delete the display ofthe first image by the delete control component, a processing in which apredetermined image whose density and color is uniform is displayed inplace of the first image. If a predetermined image is displayed insteadof the first image, since the predetermined image can be a backgroundwith respect to the contents with which the electronic paper is filledout by hand, the density and the color of the predetermined image can bedefined so as to facilitate the contents with which the electronic paperis filled out by hand to be read by the reading component (for example,if the electronic paper is of a self-light emitting type, the densityand the color of the predetermined image are defined so as to providethe background with a low brightness, or the like). Then, the readingcomponent obtains image data of the second image that represents thecontents with which the electronic paper is filled out by hand byoptically reading the electronic paper from which the display of thefirst image has been deleted by the delete control component.

In this way, also in the second aspect of the present invention, sincethe electronic paper is optically read to digitize the contents withwhich the electronic paper is filled out by hand, when the electronicpaper is filled out by hand, it is possible to use a tool which altersoptical characteristics (such as a light reflectance and the like) at aportion of the electronic paper which is filled out by hand, forexample, a pen which is highly in general use and structured such that amedium is filled out by being deposited with ink. Accordingly, use of aspecial device such as an electro-magnetic/heat-generating pen becomesunnecessary. Further, since the electronic paper can be read after thefilling-out by hand on the electronic paper has been completed, when theelectronic paper is filled out by hand, fixing of the electronic paperat a predetermined position on the digitizer becomes unnecessary.Consequently, the filling-out by hand on the electronic paper isfacilitated.

Further, since the reading component according to the second aspect ofthe present invention optically reads the electronic paper in the statein which only the contents with which the electronic paper is filled outby hand is displayed thereon, the reading result by the readingcomponent represents the second image which represents the contents withwhich the electronic paper is filled out by hand. Accordingly, imagedata of the second image can be obtained through the reading by thereading component. As the reading component according to the secondaspect of the present invention can use a general reading component suchas a scanner, also in the second aspect of the present invention, use ofa special device such as a digitizer in order to digitalize contentswith which electronic paper is filled out by hand becomes unnecessary.Consequently, in accordance with the second aspect of the presentinvention, the filling-out by hand on the electronic paper can befacilitated, and digitization of contents with which the electronicpaper is filled out by hand can be realized with a simple structure.

An electronic paper reading device according to a third aspect of thepresent invention comprises a reading component for optically reading anelectronic paper which is filled out by hand in a state in which a firstimage which is recorded in advance on the electronic paper is beingdisplayed, wherein the electronic paper is filled out by hand by usingink having characteristics such that a reflectance of the ink isdifferent from that of the electronic paper within a predeterminedwavelength region in which a difference of at least one of a reflectanceand a light emitting energy between a portion on the electronic paper atwhich the first image is recorded and a portion on the electronic paperat which the first image is not recorded is less than a predeterminedvalue, and the reading component obtains image data of a second imagethat represents contents with which the electronic paper is filled outby hand by optically reading the electronic paper by using a sensor,which is sensitive to the predetermined wavelength region.

In accordance with the third aspect of the present invention, theelectronic paper is filled out by hand by using ink havingcharacteristics in which a reflectance of the ink is different from thatof the electronic paper within a predetermined wavelength region inwhich a difference of a reflectance (in a case in which the electronicpaper is of a reflective type) or a light emitting energy (in a case inwhich the electronic paper is of a self-light emitting type) between aportion at which the first image is recorded on the electronic paper anda portion at which the first image is not recorded thereon is less thana predetermined value. In the third aspect of the present invention, theelectronic paper, which is filled out by hand by using theaforementioned ink, is optically read by the reading component.

In this way, also in the third aspect of the present invention, sincethe contents with which the electronic paper is filled out by hand isdigitized by optically reading the electronic paper, when the electronicpaper is filled out by hand, although ink itself is not in general use,any writing tool having a general structure such as a pen in which amedium is filled out by being deposited with ink can be used.Accordingly, use of special devices such as theelectromagnetic/heat-generating pen and the like becomes unnecessary.Further, since the electronic paper can be read after the filling-out byhand on the electronic paper has been completed, when the electronicpaper is filled out by hand, fixing of the electronic paper at apredetermined position on the digitizer becomes unnecessary.Consequently, the filling-out by hand on the electronic paper can befacilitated.

Since the reading component according to the third aspect of the presentinvention optically reads the electronic paper by a sensor which issensitive to a predetermined wavelength, the reading result by thereading component represents the second image that represents thecontents with which the electronic paper is filled out by hand, wherebyimage data of the second image can be obtained through the reading bythe reading component. Further, the reading component according to thethird aspect of the present invention, although a region of thesensitivity itself of the sensor is not general, can adopt the readingcomponent having a general structure such as a scanner. Accordingly,also in the third aspect of the present invention, when contents withwhich the electronic paper is filled out by hand are digitized, use of aspecial device such as a digitizer becomes unnecessary. Consequently,the filling-out by hand on the electronic paper can be facilitated, andthe digitization of contents with which the electronic paper is filledout by hand can be realized with a simple structure.

Any one of the first, second and third aspects of the present inventionfurther comprises a control component which controls to recognizeidentification information for identifying the electronic paper which isfilled out by hand, and associate the obtained image data of the secondimage with the recognized identification information.

The identification information for identifying the electronic paper,which is filled out by hand, is recognized by the control component. Theidentification information is recorded in advance on each electronicpaper, and the identification information, which has been recorded, inadvance on the electronic paper which is filled out by hand can be readand recognized. Alternatively, when image data of the second image isobtained, identification information is provided for the image data, andthe identification information can be recorded on the correspondingelectronic paper.

The control component controls to associate the obtained image data ofthe second image with the identification information. Accordingly, forexample, when each of a plurality of image data of the second imagesobtained by optically reading each of a plurality of the electronicpapers each of which is filled out by hand is controlled by the controlcomponent, a desired second image is detected by using identificationinformation that corresponds to the desired second image as a key,whereby image data of the desired second image can be easily extracted.Consequently, reuse of the second image which is represented by theextracted image data (contents with which the electronic paper is filledout by hand) can be facilitated by displaying the second image on theelectronic paper as an image, or the like.

It is desirable that the third aspect of the present invention furthercomprises a detection component for detecting a relationship betweenorientation of the electronic paper or the first image, and that of thesecond image, wherein, based on the relationship that is detected by thedetection component, the control component controls the image data ofthe second image to orient the first image and the second image in thesame direction when both of the first image and the second image arerecorded on the electronic paper.

The relationship between the orientation of the electronic paper andthat of the second image can be detected such that a mark indicating theorientation of the electronic paper (e.g. mark that points a verticaldirection or a transverse direction of the electronic paper) or the likeis recorded on the electronic paper beforehand. When the electronicpaper is optically read, the mark is read at the same time. Theorientation of the electronic paper is detected based on the mark or thelike which is contained in the reading result. Accordingly, based on thedetected orientation of the electronic paper, orientation of the secondimage obtained through the reading can be detected. Further, in anaspect in which the identification information for identifying imagedata of the first image or a storage location of the image data isrecorded on the electronic paper, the information is previously recordedat a predetermined position on the electronic paper at which theorientation of the electronic paper can be determined (at a position atwhich the electronic paper is displaced from the center thereof). Whenthe information is read, the recording position of the information isalso detected, whereby the orientation of the electronic paper can bedetected.

Regarding the relationship between the orientation of the first imageand that of the second image, for example, when the first image isrecorded on the electronic paper, the orientation of the first image isdetected. The orientation of the first image in reference to theorientation of the electronic paper is detected and recorded. When theelectronic paper which has been filled out by hand is optically read,the orientation of the electronic paper is detected, and the orientationof the first image is detected based on the orientation of the firstimage in reference to the orientation of the detected and recordedelectronic paper. In reference to the detected orientation of the firstimage, the orientation of the second image obtained through the readingis determined. Accordingly, the relationship between the orientation ofthe first image and that of the second image can be detected.

Based on the relationship detected by the detection component, when thefirst image and the second image are recorded on the electronic paper,since the image data of the second image is controlled thereby allowingthe first image and the second image to be oriented in the samedirection (for example, information indicating the detected relationshipby the detection component is stored or image data of the second imagecan be stored after receiving a rotational processing or the like inaccordance with the detected relationship), even when the second imagethat represents contents with which the electronic paper is filled outby hand is redisplayed by being recorded as an image on the electronicpaper, the second image can be displayed on the electronic paper in thesame orientation as that when the electronic paper is filled out byhand.

A fourth aspect of the present invention is an electronic paper readingsystem, which comprises an electronic paper reading device, and acontrol device, wherein the electronic paper reading device and thecontrol device are connected to each other via a network so as to beable to communicate with each other, the electronic paper reading deviceincluding a reading component for optically reading an electronic paperwhich is filled out by hand, in a state in which a first image which hasbeen recorded on the electronic paper in advance, is being displayed, arecognition component for recognizing the first image, and an extractingcomponent for extracting image data of a second image that representscontents with which the electronic paper is filled out by hand, based ona recognizing result of the first image by the recognition component anda reading result due to the reading component, and wherein the controldevice recognizes identification information for identifying theelectronic paper which is filled out by hand, and associates theobtained image data of the second image with the identificationinformation and manages the image data.

A fifth aspect of the present invention is an electronic paper readingmethod, which comprises the steps of (a) optically reading an electronicpaper which is filled out by hand in a state in which a first imagewhich has been recorded on the electronic paper in advance, is beingdisplayed, (b) recognizing the first image, and (c) based on arecognized result from the first image in the step (b), extracting, froma result of the reading in the step (a), image data of a second imagethat represents contents with which the electronic paper is filled outby hand.

As described above, the present invention exhibits an excellent effectin that the electronic paper which is filled out by hand is opticallyread in a state in which the first image is displayed thereon, and basedon the recognizing result of the first image, image data of the secondimage representing contents with which the electronic paper is filledout by hand is extracted from the reading result. Consequently, thefilling-out by hand on the electronic paper is facilitated, anddigitization of the contents with which the electronic paper is filledout by hand can be realized with a simple structure.

Further, the present invention exhibits an excellent effect in that adisplay of the first image is deleted from the electronic paper which isfilled out by hand in a state in which the first image is displayedthereon, and the electronic paper from which the display of the firstimage has been deleted is optically read, whereby image data of thesecond image which represents contents with which the electronic paperis filled out by hand is obtained. Consequently, the filling-out by handon the electronic paper is facilitated, and digitization of the contentswith which the electronic paper is filled out by hand can be realizedwith a simple structure.

Moreover, the present invention exhibits an excellent effect in that, inthe state in which a first image which is recorded in advance on theelectronic paper is displayed, the electronic paper which is filled outby hand by using ink having characteristics in which a reflectance ofthe ink is different from that of the electronic paper within apredetermined wavelength region in which a difference of at least one ofa reflectance and a light emitting energy between a portion at which thefirst image is recorded on the electronic paper and a portion at whichthe first image is not recorded thereon is less than a predeterminedvalue is optically read by using a sensor which is sensitive to thepredetermined wavelength region, whereby image data of the second imagethat represents the contents with which the electronic paper is filledout by hand is obtained. The filling-out by hand on the electronic paperis facilitated, and digitization of the contents with which theelectronic paper is filled out by hand can be realized with a simplestructure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural block diagram illustrating anelectronic paper control device according to an embodiment of thepresent invention;

FIGS. 2A and 2B are flowcharts each illustrating contents of documentwriting processing;

FIGS. 3A and 3B are flowcharts each illustrating contents of documentcontrol processing;

FIGS. 4A and 4B are image diagrams for explaining a method of detectingorientation of electronic paper;

FIGS. 5A and 5B are image diagrams each illustrating an example of atest pattern;

FIGS. 6A and 6B are flowcharts each illustrating contents of a writtencontents reading processing according to a first embodiment of thepresent invention;

FIG. 7A is a diagram illustrating an example of spectral reflectancecharacteristics of an image portion/a non-image portion of electronicpaper and ink;

FIG. 7B is a diagram illustrating an example of spectral sensitivitycharacteristics of a reading section of electronic paper;

FIG. 8 is a diagram illustrating an example of a histogram of a displayimage of a document;

FIGS. 9A and 9B are flowcharts each illustrating a written contentsreading processing according to a second embodiment of the presentinvention; and

FIG. 10 is a flowchart illustrating contents of a written contentsreading processing according to a third embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to drawings, a detailed description of an example of anembodiment of the present invention will be made hereinafter.

First Embodiment

FIG. 1 shows an electronic paper control device 10 according to a firstembodiment of the present invention. The electronic paper control device10 is a device for writing a document (image) on the electronic paper12, reading of the document which is written on the electronic paper 12or contents with which the electronic paper 12 is filled out by hand,and controlling writing/reading with respect to the electronic paper 12,and comprised as function of an electronic paper reading deviceaccording to the present invention. A media drive 14 as an inputtingdevice for inputting image data, an image data receiving device 16, anda scanner 18 are respectively connected to the electronic paper controldevice 10.

One of various information storage media, for example, comprising amagnetic disk such as a flexible disk (FD), an optical disk such as aCD-R, an optomagnetic disk (MO), a smart media (R) which can be mountedto a digital still camera (DSC), a compact flash (R), and a memory stick(R) is set to the media drive 14. Document information indicating adocument to be written on an electronic paper is stored in the setinformation storage medium. Further, the electronic paper control device10 according to the present embodiment is able to write a documenthaving arbitrary contents on the electronic paper 12, and handlearbitrary formatted data such as text data or image data (bit map orvector data, more specifically) as document information. The media drive14 reads document information that is stored in the information storagemedium, performs a predetermined processing (such as a decompressionprocessing of data in a case in which the read document information iscompressed image data) on the read document information as necessary,and outputs the document information.

Further, the image data receiving device 16 is connected to a computernetwork such as the Internet and receives document informationindicating a document to be written on the electronic paper 12 from aninformation processing device (e.g. personal computer (PC)) via thecomputer network, performs a predetermined processing (such as adecompression processing of data in a case in which the receiveddocument information is compressed image data) on the received documentinformation as necessary, and outputs document information.

The scanner 18 irradiates light to a transmissive original document suchas a photographic film or a reflective original document such paper onwhich a document to be written (such as an image) has been recorded,photoelectrically converts light which has been transmitted to orreflected from the original document, to digitized bitmap image data bya reading sensor such as an CCD, performs a predetermined imageprocessing (such as darkness correction, density conversion, shadingcorrection or defective pixel correction) on the converted digitizedbitmap image data, and outputs the bitmap image data as documentinformation.

These inputting devices are connected to a document memory 20 of theelectronic paper control device 10. Document information which has beeninput from one of the inputting devices to the electronic paper controldevice 10 is stored in the document memory 20. Further, a controllingsection 22 and a recording section 24 are connected to the documentmemory 20.

The controlling section 22 is structured by a microcomputer comprising aCPU, an ROM, and an RAM, and an I/O port which are connected to oneanother via a bus. Further, the controlling section 22 comprises anonvolatile storage section (e.g. a hard disk drive, an EEPROM or an RAMwhich is connected to a backup power supply) 22A. The storage section22A stores therein a document writing program or a handwritten contentsreading processing program for executing a document writing processingor a handwritten contents reading processing, respectively, which willbe later described.

A conveying section 30 is connected to the controlling section 22. Theelectronic paper control device 10 is provided with a loading slot forinserting the electronic paper 12 into a machine body and also with aninsertion detecting sensor for detecting that the electronic paper 12was inserted into the machine body through the loading slot. When theinsertion detecting sensor detects that the electronic paper 12 has beeninserted, based on an instruction from the controlling section 22, theconveying section 30 conveys the inserted electronic paper 12 in adirection of the internal depth of the machine body (toward a positionat which the recording section 24 and the reading section 26 aredisposed).

When a document is written on the electronic paper 12, the controllingsection 22 reads document information that indicates a document to bewritten on the electronic paper 12 which is an object to be written(“writing-object electronic paper”, hereinafter) from the documentmemory 20, forms a writing image (such as bitmap data) of a documentbased on the read document information, and stores the writing image inthe document memory 20. The controlling section 22 instructs therecording section 24 to be operated to read from the document memory 20a writing image which corresponds to the document to be written on thewriting-object electronic paper 12 when the writing-object electronicpaper 12 is conveyed to a position of the recording section 24 at whichthe writing-object electronic paper 12 is positioned, and to write adocument on the electronic paper 12 by a predetermined recording methodbased on the read writing image.

In order to record a document on the electronic paper 12 by therecording section 24, in accordance with a type of the writing-objectelectronic paper 12, a recording method can be adopted by the electronicpaper control device 10. For example, if the writing-object electronicpaper 12 is an electronic paper using a photo-writing electronic paperusing a cholesteric liquid crystal, a recording method can be adopted bythe recording method 24 in which light which is modulated for each pixelis irradiated onto the electronic paper to thereby write a documentthereon. Further, for example, if the writing-object electronic paper 12is an electronic paper using cataphoresis, a recording method can beadopted by the recording section 24 in which a voltage is applied toelectrodes charged on the electronic paper 12 to thereby write adocument thereon.

The recording section 24 comprises a function for deleting a documentwhich was once written on the electronic paper 12 and a function forrecording arbitrary attribute information (such as control informationor writing history information which will be later described) other thanthe document which has been written on the electronic paper 12.Attribute information can be optically recorded by the same recordingmethod as the recording method of a document. When attribute informationis optically recorded on the electronic paper 12, it can be recorded ina form of code such as one or two-dimensional barcode or can be recordedas characters. Further, an IC chip is mounted on the electronic paper,and attribute information can be recorded on the IC chip.

When attribute information is optically recorded on the electronic paper12, it is desired that attribute information is recorded at a positionout of an image recording region on the electronic paper 12, and it ispreferable that attribute information is recorded by using ink or thelike having optical characteristics in which visibility is low andreadability by a reading section 26, which will be described later, ishigh. Further, in order to record information on the IC chip, either ofa non-contact type recording method in which a recording is carried outby using electromagnetic induction and radio, and a contact typerecording method in which information is input to the IC chip via an ICchip connector can be adopted.

In the electronic paper 12 according to the present embodiment of thepresent invention, during the manufacture thereof, individual number fordistinguishing electronic papers from each other is recorded on theelectronic paper 12 in advance. The individual number can be recorded byone of the above-described recording methods. However, in order toprevent the structure of the reading section 26 which will be describedlater from being complicated, it is preferable that the recordingsection 24 is structured such that attribute information is recorded onthe electronic paper 12 in the same recording method as that of theindividual number on the electronic paper 12.

The reading section 26, which can read a document which is written onthe electronic paper 12 or contents with which the electronic paper 12is filled out by hand, attribute information, and an individual number,is connected to the controlling section 22. The reading section 26irradiates light onto the electronic paper 12, and photo-electricallyconverts the light reflected (or transmitted) through the electronicpaper 12 by using the reading sensor such as the CCD, and furtherconverts converted data to digital data. Then, the reading section 26forms image data representing the document which is written on theelectronic paper 12 or contents with which the electronic paper 12 isfilled out by hand, and outputs the image data to the controllingsection 22.

A portion for reading attribute information or individual number, of thereading section 26 can adopt a structure in accordance with a recordingmethod of attribute information on the electronic paper 12. For example,when attribute information is recorded on the electronic paper 12 as aone or two-dimensional barcode, the portion of the reading section 26comprises a barcode reader which reads the recorded barcode and decodesattribute information or the like. When attribute information or thelike is recorded as characters on the electronic paper 12, the portionof the reading section 26 can adopt a structure in which a regioncorresponding to characters which are recorded on the electronic paper12 is extracted from image data which is obtained by optically readingthe electronic paper 12, character recognition is carried out by usingimage data for the extracted region, and accordingly, attributeinformation or the like can be recognized. When attribute information orthe like is recorded on the IC chip that is mounted on the electronicpaper 12, the portion of the reading section 26 can adopt a structure inwhich attribute information or the like is read from the IC chip.Further, a method of reading attribute information from the IC chip canadopt either of a non-contact reading method and a contact readingmethod.

A cleaning section 28, which has a function to clean a surface of theelectronic paper 12, is connected to the controlling section 22. Acoating is applied onto a surface of the electronic paper 12 accordingto the present embodiment in order to facilitate removal of stains ordust deposited thereon or deletion of contents with which the surface ofthe electronic paper 12 is filled out by hand. The cleaning section 28can adopt a cleaning method in which a coating on the surface of theelectronic paper 12 is rinsed by using a rinsing solution. Further, inpreparation for a case in which noticeable stain or dust is deposited onthe surface of the electronic paper 12, it is preferable that thecleaning section 28 comprises a function of implementing a cleaningmethod in which, after a coating on the surface of the electronic paper12 has been stripped off, another coating is reapplied onto the surfaceof the electronic paper 12.

An interface (I/F portion) 32 is connected to the controlling section22. The I/F portion 32 comprises a display such as an LCD, which candisplay arbitrary information, and an operation panel having a pluralityof keys. Further, when attribute information is recorded as characterson the electronic paper 12, a function of reading attribute informationis not mounted on the reading section 26, and instead, charactersindicating attribute information which is recorded on the electronicpaper 12 can be read and inputted by a user via the operation panel ofthe I/F portion 32.

Further, a communication control section 34 is connected to thecontrolling section 22. The communication control section 34 isconnected to a communication network 36 such as the Internet. On theother hand, a control server 40 of a control center 38 is connected tothe communication network 36. Each of a plurality of the electronicpaper control devices 10 (FIG. 1 shows one electronic paper controldevice 10 in order to prevent confusion of the figure), which areconnected to the communication network 36, can communicate with thecontrol server 40 via the communication network 36. A mass storagemedium 42 such as an HDD (hard disk drive) is connected to the controlserver 40. The storage medium 42 stores therein a control DB (data base)44 for controlling the respective electronic papers 12 on which each ofa document is written by the electronic paper control device 10, withone electronic paper as a unit.

Next, with reference to flowcharts of FIGS. 2A and 2B, as an operationaccording to the first embodiment of the present invention, a documentwriting processing that is executed by the controlling section 22 of theelectronic paper control device 10 will be explained. Further, thedocument writing processing is implemented such that a specifiedelectronic paper 12 as the writing-object electronic paper 12 isinserted into the machine body of the electronic paper control device 10by a user who desires to write a specified document on the specifiedelectronic paper 12, and when a document which is to be written(writing-object document) on the writing-object electronic paper 12 isspecified by the user via the I/F portion 32, a document writing programis executed by a CPU at the controlling section 22.

In step 100, document information that is specified as a writing-objectdocument by a user is fetched from the document memory 20 andwriting-conditions are determined in order to write a document that isindicated by the document information on the writing-object electronicpaper 12. Further, the writing-conditions are formed by parameterscomprising a size of a writing image (a scaling ratio of a writingdocument), a writing position on the electronic paper 12, a layout ofthe writing document within the writing image (for example, whether ornot “N up” or the like is carried out to layout a plurality of pages ofthe writing documents within the writing image), a writing resolutionand the like. The writing-conditions can be determined such thatwriting-object document information is analyzed, and a value for each ofthe aforementioned parameters is set by considering a size or the likeof the writing-object electronic paper. Moreover, the writing-conditionscan be specified by a user via the I/F portion 32.

In step 102, the reading section 26 is instructed to read controlinformation from the writing-object electronic paper 12, and the controlinformation is read by the reading section 26 from the writing-objectelectronic paper 12, whereby the control information outputted from thereading section 26 is fetched. In the next step 104, individual numberfor the writing-object electronic paper 12, which is contained in thefetched control information from the reading section 26, is extractedfrom the control information. In step 106, presuming that the fetcheddocument information in step 100 is written on the writing-objectelectronic paper 12, the obtained individual number of thewriting-object electronic paper 12 in step 104 and the fetched documentinformation in step 100 are transmitted to the control server 40 of thecontrol center 38, whereby the control center 38 is requested toregister a document in the control DB 44.

A document control processing which is shown in FIGS. 3A and 3B isexecuted at the control server 40 of the control center 38 all the time.During the document control processing, in step 150, it is determinedwhether or not any information is received from one electronic papercontrol device 10. The determination in step 150 is repeated until thedetermination is affirmed. When any information is received from theelectronic paper control device 10, the determination in step 150 isaffirmed, and the processing proceeds to step 152.

The control DB 44 which is stored in the storage medium 42 of thecontrol center 38, as an example, as is shown in the following table 1,is structured such that areas for storing individual numbers anddocument control numbers are each provided for each electronic paper,and the other areas for storing a plurality of document information areeach provided for each electronic paper.

TABLE 1 <An example of contents of control DB> Individual number ofDocument electronic control Document paper number information 1 controldocument number of information document A of document A 2 controldocument number of information document B of document B 3 controldocument number of information document C of document C 4 control .number of . document A . 5 control number of document B . . . . . .

In table 1, the document control number is a number which is set by thecontrol server 40 of the control center in order to identify each ofdocument information stored in the control DB 44. In the control DB 44which is shown in table 1, document control number that corresponds to adocument that is written on each electronic paper 12 is associated withan individual number of each electronic paper 12, and registered.

The control server 40 according to the present embodiment is requestedby the electronic paper control device 10 to update the control DB 44.In the present embodiment, the number of requests from the electronicpaper control device 10 to the control server 40 is four, namely,registering a document, fetching the registered document, adding theregistered document, and deleting the registered document. In steps 152to 156, it is determined to which one of the four requests a requestthat is indicated by the received information from the electronic papercontrol device 20 corresponds.

As described above, if a request from the electronic paper controldevice 10 is to register a document, the determination in step 152 isaffirmed, and the processing proceeds to step 158, and furtherprocessings from step 158 will be carried out. Namely, in step 158, thecontrol DB 44 is detected by using the received individual number fromthe electronic paper control device 10 as a key. In the next step 160,it is determined whether or not an individual number with which thecontrol DB 44 has been detected is registered in the control DB 44.

When the writing-object electronic paper 12 is an electronic paper orthe like in which no document has been written thereon before or thelike, since no individual number or the like is registered in thecontrol DB 44, the determination in step 160 is negative, and theprocessing proceeds to step 162, where writing-object documentinformation is detected by comparing the received writing-objectdocument information from the electronic paper control device 10 withrespective document information that are registered in the control DB44. In the next step 164, it is determined whether or not thewriting-object document information is already registered in the controlDB 44.

If a writing-object document is a document, which is written only on thewriting-object electronic paper 12 among the electronic papers 12 as awhole, the determination in step 164 is also negative. In this case,since neither the received individual number nor the receivedwriting-object document information is registered in the control DB 44,in step 166, writing-object document information is newly registered inthe control DB 44 and a document control number is newly set for thisdocument information, and the received individual number is associatedwith the set document control number, and newly registered in thecontrol DB 44, and the processing returns to step 150. Accordingly, anindividual number is associated with the writing-object documentinformation through the document control number.

When the writing-object document information is already registered inthe control DB 44 (namely, when a writing-object document is a documentwhich is written on one of the other electronic papers 12), thedetermination in step 164 is affirmed, and the processing proceeds tostep 168, where the received individual number is associated with thedocument control number which has already been set based on thewriting-object document information, and newly registered in the controlDB 44, and the processing returns to step 150. Accordingly,multi-registering of the same document information in the control DB 44can be prevented, whereby storage capacity of the storage medium 42 forstoring the control DB 44 can be prevented from being unnecessarilyloaded by storing an excessive amount of document information.

On the other hand, if the writing-object electronic paper 12 is anelectronic paper on which a document has been written before, thedetermination in step 160 is affirmed, and the processing proceeds tostep 170, where a document control number, which is associated with thereceived individual number (the individual number of the writing-objectelectronic paper 12), and registered in the control DB 44, is read todetect whether or not any other individual number do exists which isassociated with the same document control number, and registered in thecontrol DB 44.

When the determination in step 170 is denied, since the document whichhas been written on the writing-object electronic paper 12 is notwritten in other documents, the processing proceeds to step 172, wherethe document information for which the document control number which hasbeen read previously was set is deleted from the control DB 44, and thenthe processing proceeds to step 176. If the determination in step 170 isaffirmed, since the document which has been written on thewriting-object electronic paper 12 is also written on other electronicpapers 12 with the obtained individual numbers, the processing proceedsto step 174, where deletion of document information from the control DB44 is not carried out but only deletion of the document control numberwhich is associated with the received individual number and registeredin the control DB 44 is carried out. Accordingly, only deletion of arelationship between the received individual number and the documentinformation which have been associated therewith is carried out, and theprocessing proceeds to step 176.

In the next step 176, the writing-object information is detected bycomparing the received writing-object document information with each ofthe document information that are registered in the control DB 44. Inthe next step 178, it is determined whether or not the writing-objectdocument information is already registered in the control DB 44. If thedetermination in step 178 is negative, the received individual number isregistered in the control DB 44. However, since no writing-objectdocument information is registered in the control DB 44, in step 180,writing-object document information is newly registered in the controlDB 44, a document control number is set to the document information, theset document control number is associated with an individual numberwhich has already been registered, and registered in the control DB 44.Thereafter, the processing returns to step 150.

If the determination in step 178 is affirmed, since both the receivedindividual number and the writing-object document information areregistered in the control DB 44, the processing proceeds to step 182,where the document control number which is set for the obtained documentinformation thus detected in step 176 is associated with the obtainedindividual number thus detected in step 158 and registered in thecontrol DB 44. Thereafter, the processing returns to step 150. By theabove-described processing, the received individual number from theelectronic paper control device 10 and the writing-object documentinformation are associated with each other at the control DB 44.

On the other hand, in the electronic paper control device 10, when thecontrol center 38 is requested to register a document in the control DB44 in step 106 during the document writing processing (FIGS. 2A and 2B),in the next step 108, the writing-object document information isconverted to bitmap data in accordance with the writing-conditionsdetermined in step 100, and a writing image for writing a writing-objectdocument on the writing-object electronic paper is formed.

In the next step 110, orientation of the writing-object electronic paper12 is detected. The electronic paper 12 according to the presentembodiment is structured such that the orientation of the electronicpaper 12 is easily detectable. Namely, as described above, controlinformation or attribute information such as writing history informationis optically recorded on the electronic paper 12 or recorded on the ICchip which is mounted on the electronic paper 12. However, if attributeinformation is optically recorded (as characters or barcodes) on theelectronic paper 12, for example, as is shown in FIG. 4A, which shows aninformation recording section, the attribute information is recorded ata position which is offset from the center of the electronic paper 12(in the vicinity of a particular corner which corresponds to a portionout of a document writing region on the electronic paper 12).

If attribute information is recorded on the electronic paper 12 asdescribed above, when the reading section 26 reads control informationfrom the writing-object electronic paper 12, a position is searched atwhich attribute information (control information) is recorded on thewriting-object electronic paper 12. Therefore, the reading section 26which has read control information from the writing-object electronicpaper 12 in step 110 is asked for a recording position of the attributeinformation (control information) on the writing-object electronic paper12. Based on the recording position of the attribute information(control information) on the writing-object electronic paper 12 providedby the reading section 26, orientation of the writing-object electronicpaper 12 can be detected.

If attribute information is recorded on the IC chip which is mounted onthe electronic paper 12, for example, as shown in FIG. 4B, detection ofthe orientation of the electronic paper 12 is facilitated by previouslyrecording a mark indicating orientation of the electronic paper 12(denoted by “orientation indication mark” in FIG. 4B) at the positionwhich is offset from the center of the electronic paper 12 (positionthat corresponds to a region out of the document writing region on theelectronic paper 12). In this case, based on a recording position of amark on the writing-object electronic paper 12, the orientation of thewriting-object electronic paper 12 can be detected.

In step 112, orientation information indicating orientation of awriting-object document is set based on orientation of thewriting-object electronic paper 12 which is detected in step 110. Anindividual number of the writing-object electronic paper 12 andwriting-condition information indicating the writing-conditions that aredetermined in step 110 are added to the set orientation information.Accordingly, control information to be written on the writing-objectelectronic paper 12 is created. Further, in step 114, the readingsection 26 is instructed to read writing history information from thewriting-object electronic paper 12, and the read writing historyinformation read from the writing-object electronic paper 12 is fetchedfrom the reading section 26.

In the present embodiment, calibration for correcting a writing image inorder to suppress fluctuations of the finish of a document, which iswritten on the electronic paper 12, is carried out. The calibration iscarried out by using calibration data that is determined in accordancewith characteristics of the electronic paper 12. However, the electronicpaper 12 has characteristics which, when a document (image) isrepeatedly written thereon, varies in accordance of the number of timesof the writing thus causing a problem in that calibration accuracydeteriorates in accordance with variation of the characteristics of theelectronic paper 12.

For this reason, the writing history information that is fetched in step114 includes the number of accumulated writing times which correspondsto an accumulated value of the number of times of writing a documentsince the manufacture of the writing-object electronic paper 12 has beencompleted (the number of the accumulated writing times is initially setto “0” during the manufacture of the electronic paper 12, and is updatedeach time a document is written on the electronic paper 12). In the nextstep 116, it is determined whether or not calibration data must beupdated based on the number of the accumulated writing times that iscontained in the writing history information that is read from thewriting-object electronic paper 12.

In the present embodiment, in order to reduce variation of finish of thewritten document on the electronic paper 12 in accordance with variationof characteristics of the writing-object electronic paper 12, thedetermination in step 116 is affirmed each time a document is written onthe electronic paper 12 at a predetermined time, and the processingproceeds to step 118, where calibration data is newly determined, andthe newly determined calibration data is used to carry out a calibrationprocessing for correcting a writing image.

More specifically, for example, a test pattern image comprising unitpatterns each of which is formed by a plurality of patches having thesame color (for example, gray) and having different densities (fourpatches whose densities are d1, d2, d3, and d4) (see FIG. 5A) aresubstantially uniformly distributed over the entire surface of a regionof the electronic paper 12 within which a document is written (see FIG.5B) is written on the writing-object electronic paper 12 by therecording section 24. Then, the test pattern image that is recorded onthe writing-object electronic paper 12 is read by the reading section26. Further, in accordance with characteristics owned by the electronicpaper 12 which is to be read (“reading-object electronic paper 12),there is a possibility that the test pattern image which is recorded ona reading-object electronic paper 12 may be affected by thecharacteristics owned by the reading-object electronic paper 12.Consequently, the finish of a written document varies such that arecording position of the test pattern image is displaced from apredetermined recording position or a gray scale of the test patternimage becomes partially uneven or the like.

For this reason, based on image data obtained by the reading portion 26reading the test pattern image, the image data is analyzed to compute aphysical amount indicating the finish of the test pattern image recordedon the writing-object electronic paper 12 (for example, a position whereimage (respective patches) is recorded and a partial variation of thegray scale (density of respective patches)) is computed. The computedvalue of the physical amount is compared with a value of the physicalamount when the test pattern image had a desired finish. Accordingly,calibration data is determined in order to obtain a desired finish whenthe test pattern image or other document (image) is recorded on thewriting-object electronic paper 12.

In step 118, based on paper calibration data which is determined due tothe above-described processing, when a writing-object document iswritten on the writing-object electronic paper 12, a writing image iscorrected such that the writing-object document on the writing-objectelectronic paper 12 has a desired finish. Further, calibration data canbe recorded on the electronic paper 12 as a writing history information(when calibration data is newly determined, the previous calibrationdata contained in the writing history information is overwritten by newcalibration data), for example. However, instead of this, calibrationdata can be registered in the control DB 44 of the control center 38.

On the other hand, in step 116, if it is determined that update ofcalibration data is not required, In step 120, calibration data isobtained from writing history information (if calibration data isregistered in the control DB 44 of the control center 38, calibrationdata is obtained from the control center 38), when the writing-objectdocument is written on the writing-object writing paper 12, a writingimage is corrected based on the calibration data such that thewriting-object document on the writing-object electronic paper 12 has adesired finish. The calibration in step 118 or step 120 can suppressvariation of the finish of the writing-object document written on thewriting-object electronic paper 12.

In the next step 122, it is determined whether or not the writing-objectelectronic paper 12 requires cleaning (cleaning of the surface of thewriting-object electronic paper 12). In the present embodiment, theelectronic paper 12 is determined to require cleaning if an accumulatedvalue of the number of times of writing a document has amounted to apredetermined value since the last time cleaning was carried out, or ina state in which the writing-object electronic paper 12 is filled out byhand and if a document which is not related to contents with which theelectronic paper 12 has been filled out by hand is written on thewriting-object electronic paper 12. The aforementioned determination isnegative, the processing proceeds to step 126 without carrying out anyprocessing. However, if the determination in step 122 is affirmed, theprocessing proceeds to step 124, where the surface of the writing-objectelectronic paper 12 is cleaned by the cleaning section 28.

In step 126, among the read writing history information from thewriting-object electronic paper 12 in step 114, the accumulated numberof times of writing a document is updated. Namely, if no processing fornewly determining calibration data is carried out, in order to write awriting-object document on a writing-object electronic paper 12, theaccumulated number of times of writing a document is increased by 1, andif calibration is also determined, since a test pattern image is writtenon the writing-object electronic paper 12, the accumulated number oftimes of writing a document is incremented by 2.

In step 128, the document (image) which is currently written on thewriting-object electronic paper 12 is deleted by the recording section24. In the next step 130, the writing image which has experiencedcalibration is used to write the writing-object document on thewriting-object electronic paper 12 by the recording portion 24. Further,in step 132, both the control information that is prepared in step 112and the writing history information that is updated in step 126 arewritten by recording section 24 on the writing-object electronic paper12. Consequently, the document writing processing is completed.

The electronic paper 12 according to the present embodiment can be usedas a medium that replaces paper. Namely, even after a writing-objectdocument is written on the electronic paper 12 as described above,characters and the like can be added thereon by hand in the same manneras in paper or the like. Further, in the first embodiment of the presentinvention, a pen (for handwriting) is prepared in use for filling out(adding) the electronic paper 12 by hand such that a user fills out(adds) the electronic paper 12 by hand by using the pen for hand.

The pen for handwriting is structured so as to fill out the electronicpaper 12 therewith by being deposited with ink. Ink for the pen forhandwriting has a spectral reflectance characteristics that is shown bya dashed line in FIG. 7 as an example. Namely, the electronic paper 12according to the present embodiment has optical characteristics suchthat a light reflectance of a portion of the electronic paper 12 onwhich a document is written (portion at which the density varies bywriting a document such as a portion corresponding to characters, of adocument which is consisted of characters (hereinafter, “imagingportion”)) has a light reflectance that is different from that of aportion of the electronic paper 12 which is extended to a predeterminedwavelength region including at least a visible region and at which nodocument is written (portion at which density is not changed in spite ofa document writing, for example, a portion not including characters inthe document which is consisted of characters (portion which correspondsto a background portion) (hereinafter, “non-imaging portion”). However,ink for the pen for handwriting has optical characteristics such that alight reflectance within at least a predetermined wavelength region isdifferent from that of each of an imaging portion and a non-imagingportion of the electronic paper 12.

If a user who filled out the electronic paper 12, on which apredetermined document has already been written, by hand with the penfor handwriting, desires to digitize contents with which the electronicpaper 12 was filled out by hand, the electronic paper 12 which wasfilled out by hand with the pen for handwriting is inserted into amachine body of the electronic paper control device 10 by the user. Theinserted electronic paper 12 is instructed to read the contents withwhich the electronic paper 12 was filled out by hand. Accordingly, ahandwritten contents reading program is executed by a CPU of thecontrolling section 22, and a handwritten contents reading processingwhich is shown in FIGS. 6A and 6B is carried out by the controllingsection 22.

During the handwritten contents reading processing, first, in step 220,the reading section 26 is instructed to read control information fromthe electronic paper 12 (the reading-object electronic paper 12) whichis inserted into the machine body of the electronic paper control device10. Control information is read from the reading-object electronic paper12. Then, the outputted control information from the reading section 26is fetched. Further, in step 222, writing-condition information that iscontained in the control information fetched from the reading section 26is obtained from the control information.

In step 224, orientation of the reading-object electronic paper 12 canbe detected such that, if attribute information including controlinformation is optically recorded at a position which is offset from thecenter of the electronic paper 12, the reading section 26 is inquired ofa recording position of attribute information (control information) onthe reading-object electronic paper 12. Accordingly, orientation of thereading-object electronic paper 12 can be detected based on therecording position of attribute information (control information) on thereading-object electronic paper 12 that is informed from the readingsection 26. Further, if the orientation indicating mark (see FIG. 4B) ispreviously recorded at a position which is offset from the center of theelectronic paper 12, orientation of the reading-object electronic paper12 can be detected based on the recording position of the mark on thereading-object electronic paper 12.

In step 226, orientation information that indicates orientation of thewritten document is obtained based on the orientation of the electronicpaper 12, from the reading control information from the reading-objectelectronic paper 12 in step 220. Further, in step 228, based on thedetected orientation of the reading-object electronic paper 12 in step224 and the obtained orientation information in step 226, orientation ofthe written document on the reading-object electronic paper 12 isrecognized. Then, in step 230, based on a relationship between therecognized orientation of the document in step 228 and a readingdirection in which the reading-object electronic paper 12 is read by thereading section 26, parameters are defined to apply a correctionprocessing to image data that represents contents with which theelectronic paper 12 is filled out by hand (handwritten image thatcorresponds to second image data according to the present invention).

In the first embodiment of the present invention, the aforementionedhandwritten image is separated and extracted from the image data (theread image) resulting from reading the reading-object electronic paper12 by the reading section 26 (a detailed description thereof will begiven later). However, in the present embodiment, the handwritten imagewhich was separated and extracted from the image data is subjected tocorrection processing including a rotation processing, a page dividingprocessing and a scaling processing, such that a written image forwriting a composite image in which a document and the handwrittencontents are overlapped with each other on the electronic paper 12 isgenerated simply by overlapping the separated and extracted handwrittenimage with a writing image of the document which is written on thereading-object electronic paper 12. In addition, the above-describedsteps 224 to 230 correspond to a detection component of the presentinvention.

In step 230, based on the orientation of the written document and thereading direction by the reading section 26, parameters during therotation processing (for example, a rotational direction or a rotationalamount) are defined, and if a plurality of pages of documents is writtenon the reading-object electronic paper 12 (for example, N up or thelike), parameters during the page dividing processing (for example, thenumber of divisions or a divisional boundary position) are defined, andparameters during the scaling processing (for example, a scaling ratio)are also defined. Further, besides the aforementioned correctionprocessing, the handwritten image is also subjected to a well knowncorrection processing (such as an isolated point removal processing forremoving points which are isolated within an image and which have a highpossibility of being dust or the like or a narrow line processing inwhich narrow lines are thickened and then thinner to prevent narrowlines from being broken or blurred, or the like) by using an opticalcharacter reader (OCR). However, in step 230, parameters for suchprocessings are also defined.

After definition of parameters for the correction processing has beencompleted, in the next step 232, the reading-object electronic paper 12is read by the reading section 26. Further, as shown in FIG. 7A bydenoting as “CH1”, the reading section 26 according to the firstembodiment of the present invention reads the reading-object electronicpaper 12 by using a sensor having spectral sensitivity characteristicsthat is sensitive only to the first wavelength region within which alight reflectance of the imaging portion and that of the non-imagingportion of the electronic paper 12, and that of ink for the hand pen aredifferent from one another. Further, step 232 and the reading section 26for actually reading the electronic paper 12 correspond to a readingcomponent of the present invention. In further steps from the next step234, a processing is carried out in which the handwritten image (imagedata representing the handwritten contents) is separated from the readimage resulting from reading by the reading section 26.

Namely, in step 234, individual number of the reading-object electronicpaper 12 is obtained from the control information read from thereading-object electronic paper 12 in step 220. The individual number ofthe reading-object electronic paper 12 which is contained in the controlinformation corresponds to identification information of the presentinformation. Further, in step 236, the obtained individual number of thereading-object electronic paper 12 in step 234 is transmitted to thecontrol server of the control center 38, and the control center 38 isrequested to fetch the document information that is associated with theindividual number and registered in the control DB 44 (documentinformation of the document which is written on the reading-objectelectronic paper 12). In step 238, it is determined whether or not thedocument information is received from the control center 38, and theprocessing waits until the determination is affirmed. Moreover, steps232 to 238 correspond to a recognition component of the presentinvention.

When the control server 40 of the control center 38 is requested tofetch the document information from the electronic paper control device10, the determination in step 150 during the document control processing(FIGS. 3A and 3B) is affirmed, and the determinations in steps 152 and154 are negative, and the determination in step 156 is affirmed, and theprocessing proceeds to step 184, where the control DB 44 is detectedwith the received individual number from the electronic paper controldevice 10 as a key. Then, in the next step 186, it is determined whetheror not the detected individual number is registered in the control DB44.

If the determination in step 186 is negative, the processing proceeds tostep 190, and returns an error response to the electronic paper controldevice 10 as a sender of individual information. However, if thedetermination in step 186 is affirmed, the processing proceeds to step188, where the document information that is associated with the obtainedindividual number by the detection and registered in the control DB 44is read from the control DB 44, and the read document information istransmitted to the electronic paper control device 10 as the sender ofthe individual information. Thereafter, the processing returns to step150.

At the electronic paper control device 10 side, when the documentinformation is received from the control server 40, the determination instep 238 during the handwritten contents reading processing (see FIGS.6A and 6B) is affirmed, the processing proceeds to step 240. In step240, based on the writing-conditions indicated by the obtainedwriting-condition information from the control information in step 222and the recognized orientation of a document in step 228, the receiveddocument information from the control server 40 is converted to bitmapdata to form a display image of document information which represents astate in which the document represented by the document information isdisplayed on the read image resulting from reading the electronic paper12 in the previous step 232.

In step 242, data for simple image pixel that corresponds to the imagingportion of the electronic paper 12 is fetched from the display image ofthe document information that is formed in step 240, and correspondingimage pixel data is fetched from the read image as data for image pixelswhich are supposed to receive a processing. The densities of pixels thatare expressed by both pixel data thus fetched are compared to eachother. In the next step 244, it is determined whether or not a densitydifference between the both fetched pixel is a predetermined value ormore.

As shown in FIG. 7B by denoting as “CH1”, since the reading section 26according to the first embodiment of the present invention reads theelectronic paper 12 within the first wavelength region within which thelight reflectance of the imaging portion and that of the non-imagingportion, of the electronic paper 12, and that of ink for the handwritingpen are different from one another, if a density difference betweenimage pixels which pixels are subjected to a processing on the readimage and corresponding pixel density on the display image of thedocument information is less than a predetermined value, the imagepixels which are subjected to a processing on the read image can bedetermined to be those corresponding to a portion which is not depositedwith ink for the handwriting pen. For this reason, if the determinationin step 244 is negative, the processing proceeds to step 246, where avalue of the density of the image pixels which are subjected to aprocessing on the read image is converted to that corresponding to thenon-imaging portion. Thereafter, the processing proceeds to step 248.

On the other hand, when a difference between a density of the imagepixels which are subjected to a processing on the read image and that ofthe corresponding pixels on the display image of the documentinformation is a predetermined value or more, the image pixels which aresubjected to a processing on the read image are image pixels thatcorrespond to portions of the electronic paper which is filled out byhand (portions that are deposited with ink for the handwriting pen).When the density of the image pixels is converted to a density valuethat corresponds to the non-imaging portion as described above, it canbe determined that the contents with which the electronic paper 12 isfilled out by hand by the user are deleted from the read image.Accordingly, if the determination in step 244 is affirmed, no processingis carried out, and the processing proceeds to step 248.

In step 248, it is determined whether or not the all of the image pixelsthat correspond to the imaging portion of the display image of thedocument information have received further processings from step 242. Ifthe determination is negative, the processing returns to step 242, andthen, steps 242 to 248 are repeated until the determination in step 248is affirmed. Accordingly, among the read images resulting from readingthe reading-object electronic paper 12, portions which correspond to theimaging portion and which are not deposited with ink for the handwritingpen are deleted, and accordingly, the handwritten image (bitmap imagedata that represents contents with which an electronic paper is filledout by hand) is separated and extracted from the read image.

The above-described steps 240 to 248 correspond to an extractingcomponent of the present invention, and the display image of thedocument information which is formed in step 240 corresponds to theresult from “estimating a first image due to the reading by the readingcomponent” of the present invention.

Separation and extracting of the handwritten image from the read imageis not limited to those due to the comparison between the density on theread image and that of the document information on the display image.For instance, if the written document on the electronic paper 12 is abinary image as in the document which is consisted of characters, as isshown as an example in FIG. 8, the handwritten image can be separatedand extracted such that a density histogram of the display image of thedocument information is created. A density range, from which portionscorresponding to a bottom portion of the density histogram have beendeleted, is defined. Among respective image pixels of a reading image,only image pixels having a density within a range of the defined densityare converted to a density of the non-image portion.

Further, if a positional accuracy of the reading-object electronic paper12 (more specifically, a positional accuracy of the reading-objectelectronic paper 12 in reference to the reading section 26) isinsufficient, the read image and the display image of documentinformation are each divided into strip-shaped blocks in a verticaldirection, and also divided into strip-shaped blocks in a transversedirection. Among edge portions within the image, an edge portion whosedistance to an end portion of a block is the shortest (a verticaldistance for a block divided in a vertical direction and a transversedistance for a block divided in a transverse direction) is obtained foreach block. A distance between the obtained edge portion and the endportion of the block is compared with each corresponding block pair. Adistance difference of a block pair whose distance difference is small(a block pair that is estimated to have been scarcely affected bycontents with which the electronic paper 12 is filled out by hand) canbe used as a displacement amount of a position in a vertical/transversedirection (a mean or intermediate value of distance differences of blockpairs can also be used) to determine corresponding image pixels betweenthe read image and the display image of document information.

If the determination in step 248 is affirmed, the processing proceeds tostep 250, where a correction processing (comprising a rotationalprocessing, a page dividing processing, a scaling processing, anisolated point removal processing, and a narrow line processing) of thehandwritten image which is separated and extracted from the read imageis performed in accordance with the parameters defined in the previousstep 230. Further, step 250 (particularly a rotational processing out ofvarious correction processings that are carried out in step 250)constitutes a control component of the present invention. Then, in step252, the handwritten image which has experienced the correctionprocessing, and the obtained individual number of the reading-objectelectronic paper 12 in step 234 are transmitted to the control server 40of the control center 38. The control center 38 is requested to add andregister the handwritten image into the control DB 44. The handwrittencontents reading processing is completed.

When the control server 40 of the control center 38 is requested by theelectronic paper control device 10 to add and register the handwrittenimage thereinto, the determination in step 150 during the documentcontrol processing (FIGS. 3A and 3B) is affirmed, and the determinationin step 152 is negative, while the determination in step 154 isaffirmed. The processing proceeds to step 192, where the control DB 44is detected by using the received individual number from the electronicpaper control device 10 as a key. In the next step 194, it is determinedwhether or not the detected individual number is registered in thecontrol DB 44.

If the determination in step 194 is negative, the processing proceeds tostep 190, where an error response is returned to the electronic papercontrol device 10 as an original information sender. However, thedetermination in step 194 is affirmed, the processing proceeds to step196, where document information which is associated with the obtainedindividual number and is registered in the control DB 44 is read fromthe control DB 44, and the received handwritten image from theelectronic paper control device 10 is added to the read documentinformation. Accordingly, document information that indicates thewritten document on corresponding electronic paper 12 and contents withwhich the electronic paper 12 is filled out by hand is newly created.Then, in the next step 198, the newly created document information isassociated with the obtained individual number thus detected, andregistered in the control DB 44, and the processing returns to step 150.

Then, if the control center 38 is requested by the electronic papercontrol device 10 to fetch document information, document information towhich the handwritten image has been added is read from the control DB44, and transmitted to the electronic paper control device 10.Accordingly, the electronic paper control device 10 which has receivedthe document information can easily write a composite image of contentswith which the electronic paper 12 is filled out by hand and which arerepresented by the handwritten image, and the document indicated by thedocument information, on the electronic paper 12 from which the contentshave been deleted. Consequently, the control center 38 (the controlserver 40 and the storage medium 42) corresponds to the controlcomponent of the present invention.

If the electronic paper control device 10 deletes a document which iswritten on the electronic paper 12 (or image in which the contents, withwhich the electronic paper 12 is filled out by hand and which arerepresented by the handwritten image, are synthesized with thedocument), an individual number of the electronic paper 12 from which adocument or the like is deleted is transmitted from the electronic papercontrol device 10 to the control server 40 of the control center 38, andthe control center 38 is requested to delete corresponding documentinformation registered in the control DB 44.

In this case, the determination in step 150 during the document controlprocessing (FIGS. 3A and 3B) is affirmed, and the determinations insteps 152 to 156 are affirmed, and the processing proceeds to step 200,where the control DB 44 is detected by using the received individualnumber from the electronic paper control device 10 as a key. In the nextstep 202, it is determined whether or not the individual number withwhich the control DB 44 is detected is registered in the control DB 44.Then, if the determination is negative, the processing proceeds to step204, where an error response is returned to the electronic paper controldevice 10 as the original information sender. However, the determinationin step 202 is affirmed, the processing proceeds to step 206, where adocument delete processing (the same processing as described in steps170 to 174) is carried out.

Therefore, information that is associated with the individual number ofeach electronic paper 12 and registered in the control DB 44 of thecontrol center 38 is appropriately updated so as to always correspond tothe written contents on each electronic paper 12.

In the above-description, a description of an example has been made inwhich an electronic paper is filled out by hand by using a pen forhandwriting having the structure in which the electronic paper isdeposited with ink having the spectral reflectance characteristics asshown by a dashed line in FIG. 7A. However, in the handwritten contentsreading processing according to the first embodiment of the presentinvention, if a density of a portion of the electronic paper which isfilled out by hand and that of an imaging portion of the electronicpaper are different from each other, the handwritten image can beseparated and extracted from the read image. Accordingly, when theelectronic paper 12 is filled out by hand, any writing tool can be usedas long as it satisfies the above-described conditions.

Second Embodiment

Next, a second embodiment of the present invention will be described.Further, since the second embodiment of the present invention isstructured in the same manner as the first embodiment of the presentinvention, portions identical to those shown in the first embodiment aredenoted by the same reference numerals and a description thereof will beomitted. Hereinafter, with reference to flowcharts of FIGS. 9A and 9B, ahandwritten contents reading processing according to the secondembodiment of the present invention will be explained, as an operationof the second embodiment of the present invention,

In step 270, the reading section 26 is instructed to read controlinformation from the reading-object electronic paper 12, controlinformation is read from the reading-object electronic paper 12, and theoutputted control information from the reading section 26 is fetched.Further, in step 272, an individual number of the reading-objectelectronic paper 12, which is contained in the reading controlinformation from the reading-object electronic paper 12, is obtainedfrom the control information. In step 274, the obtained individualnumber of the reading-object electronic paper 12 in step 272 istransmitted to the control server 40 of the control center 38, and thecontrol center 38 is requested to fetch document information which isassociated with the individual number and registered in the control DB44 (document information of a document which is written on thereading-object electronic paper 12). In step 276, it is determinedwhether or not document information is received from the control center38, and the processing waits until the determination is affirmed.

When document information is received from the control sever 40 of thecontrol center 38, the determination in step 276 is affirmed, and theprocessing proceeds to step 278, where writing-condition informationthat is contained in the reading control information from thereading-object electronic paper 12 is obtained from the controlinformation. In the next step 280, orientation of the reading-objectelectronic paper 12 is detected in the same manner as in step 224 duringthe handwritten contents reading processing (FIGS. 6A and 6B) accordingto the first embodiment of the present invention. Further, in step 282,orientation information, which indicates orientation of a document to bewritten when the orientation of the electronic paper 12 is referenced,is obtained from the reading control information from the reading-objectelectronic paper 12. In the next step 284, based on the detectedorientation of the reading-object electronic paper in step 280 and theobtained orientation information in step 282, orientation of the writtendocument on the reading-object electronic paper 12 is recognized.

In step 286, the reading section 26 is instructed to read writinghistory information from the reading-object electronic paper 12, and theread writing history information from the reading-object electronicpaper 12 by the reading section 26 is fetched. Further, in step 288,based on a relationship between the recognized orientation of documentin step 284 and a direction in which the reading section 26 reads thereading-object electronic paper 12, in the same manner as in step 230during the handwritten contents reading processing according to thefirst embodiment of the present invention (FIGS. 6A and 6B), parametersfor the correction processing that are defined for image data(handwritten image) representing contents with which an electronic paperis filled out by hand.

In step 290, a document which is written on the reading-objectelectronic paper 12 is deleted by the recording section 24. Further,step 290 corresponds to a delete control component of the presentinvention. Further, in step 292, the reading-object electronic paper 12is read by the reading section 26. Step 292 and the reading section 26which actually reads the reading-object electronic paper 12 correspondto a reading component of the present invention.

At this point, in the present embodiment, since a document which iswritten on the reading-object electronic paper 12 has been deletedtherefrom, the reading-object electronic paper 12 is in a state ofindicating only contents with which the reading-object electronic paper12 is filled out by hand. Accordingly, such a complicated processing asin the handwritten contents reading processing of the first embodimentof the present invention (see FIGS. 6A and 6B) is not required, andinstead, by simply reading the reading-object electronic paper 12 instep 292, the handwritten image, which represents contents with whichthe reading-object electronic paper 12 is filled out by hand, can beobtained.

In step 294, various correction processings are conducted on thehandwritten image that is obtained by the reading in step 292 by usingthe parameters defined in the previous step 288 in the same manner as instep 250 during the handwritten contents reading processing (FIGS. 6Aand 6B) according to the first embodiment of the present invention. Instep 296, the handwritten image which has experienced the correctionprocessings, and the obtained individual number of the reading-objectelectronic paper 12 in step 272 are transmitted to the control server 40of the control center 38, and the control center 38 is requested to addand register the handwritten image into the control DB 44. Accordingly,as described in the first embodiment of the present invention, thehandwritten image that is transmitted to the control center 38 is addedand registered into the control DB 44.

In step 298, in accordance with the writing-conditions that areindicated by the obtained writing-condition information from controlinformation in the previous step 278, and the recognized orientation ofthe document in the previous step 284 (the orientation of the documentwhich has been written on the reading-object electronic paper 12), thereceived document information from the control server 40 of the controlcenter 38 is converted to bitmap data. Accordingly, a writing image isformed for rewriting the document that has been written on thereading-object electronic paper 12 (the document which has been deletedfrom the reading-object electronic paper in step 290) on thereading-object electronic paper 12.

In step 300, among the writing history information that is read from thereading-object electronic paper 12 in step 286, the accumulated numberof times of the writing history is incremented by 1 in preparation for acase of rewriting a document, whereby the writing history is updated.Then, in step 302, the recording section 24 rewrites a document on thereading-object electronic paper 12 by using the writing image that hasbeen formed in step 298. Further, in step 304, the recording section 24writes control information and the updated writing history informationin step 300 on the reading-object electronic paper 12. Accordingly, thehandwritten contents reading processing is completed.

Third Embodiment

A description of a third embodiment of the present invention will bemade hereinafter. Further, portions identical to those shown in thefirst and second embodiments are denoted by the same reference numeralsand a description thereof will be omitted.

As shown in FIG. 7B by denoting as “CH2”, the reading section 26according to the third embodiment of the present invention is structuredto read the electronic paper 12 by using a sensor having spectralsensitivity characteristics which is sensitive only to a secondwavelength region within which light reflectances of an imaging portionand a non-imaging portion of the electronic paper 12 are substantiallythe same, and a light reflectance of ink for a pen for handwriting isdifferent from those of the imaging portion and the non-imaging portionof the electronic paper 12.

With reference to a flowchart of FIG. 10, a handwritten contents readingprocessing according to the third embodiment of the present inventionwill be explained. In step 320, the reading section 26 is instructed toread control information from the reading-object electronic paper 12.Control information is read from the reading-object electronic paper 12.The outputted control information from the reading section 26 isfetched. Further, in step 322, writing-condition information that iscontained in the reading control information from the reading-objectelectronic paper 12 is obtained from the control information.

In the same manner as in the steps 224 to 230 during the handwrittencontents reading processing according to the first embodiment of thepresent invention (FIGS. 6A and 6B) and in the same manner as in thesteps 280 to 284, 288 during the handwritten contents reading processingaccording to the second embodiment of the present invention (FIGS. 9Aand 9B), in the next steps 324 to 330, orientation of the reading-objectelectronic paper 12 is detected (step 324), orientation information isobtained from the reading control information from the reading-objectelectronic paper 12 (step 326), orientation of a document which iswritten on the reading-object electronic paper 12 is recognized (step328), and parameters for a correction processing of the handwrittenimage are defined (step 330).

In step 332, the reading-object electronic paper 12 is read by thereading section 26. Further, this step 332, together with the readingsection 26 for reading the reading-object electronic paper 12 correspondto the reading component of the present invention.

As described above, as is shown in FIG. 7B by denoting as “CH2”, thereading section 26 according to the third embodiment of the presentinvention reads the electronic paper 12 by using a sensor havingspectral sensitivity characteristics which is sensitive only to a secondwavelength region within which light reflectances of the imaging portionand the non-imaging portion of the electronic paper 12 are substantiallythe same, and a light reflectance of ink for a pen for handwriting isdifferent from those of the imaging portion and the non-imaging portionof the electronic paper 12. Accordingly, a complicated processing suchas the separation of the handwritten image from the read image as in thehandwritten contents reading processing according to the firstembodiment of the present invention (FIGS. 6A and 6B) is not required,and instead, the reading-object electronic paper 12 is simply read instep 332, whereby the handwritten image representing contents with whichthe reading-object electronic paper 12 is filled out by hand (sometimesreferred to as “handwritten contents”) can be obtained.

In step 334, in the same manner in step 250 during the handwrittencontents reading processing (FIGS. 6A and 6B) according to the firstembodiment of the present invention, and in step 294 during thehandwritten contents reading processing (FIGS. 9A and 9B), variouscorrection processings are conducted on the handwritten image resultingfrom reading in step 332 by using the parameters defined in the previousstep 330. Further, in step 336, an individual number of thereading-object electronic paper 12 is obtained from the reading controlinformation from the reading-object electronic paper 12 in the previousstep 320.

Then, in step 338, the handwritten image which has experienced acorrection processing, and the obtained individual number of thereading-object electronic paper 12 in step 336 are transmitted to thecontrol server 40 of the control center 38, and the control center 38 isrequested to add and register the handwritten image into the control DB44. Accordingly, the handwritten image that is transmitted to thecontrol center 38 is added and registered to the control DB 44.

In the above-description, when the document which is represented bydocument information and the handwritten contents which are representedby the handwritten image are written on the electronic paper 12, inorder to orient both the document and the handwritten contents in thesame direction, an example has been explained in which the handwrittenimage which has previously received a rotational processing isregistered in the control DB 44. However, instead of this, informationindicating a relationship between orientation of the document which iswritten on the electronic paper 12 and that of the contents with whichthe electronic paper 12 is filled out by hand, and the handwritten imageare previously registered in the control DB 44, and when the documentrepresented by document information and the handwritten contentsrepresented by a handwritten image are written on the electronic paper12, a rotational processing can be conducted on the handwritten imagebased on the aforementioned information. The present invention alsocontains the above-described aspect.

Further, in the above-description, an example has been explained inwhich handwritten image (or information containing the handwrittenimage) representing contents with which the electronic paper 12 isfilled out by hand is associated with each individual number of eachelectronic paper 12 and then controlled at the control center 38.However, the present invention is not limited to this, and instead,identification information of each electronic paper 12 can be associatedwith handwritten image or document information corresponding to eachelectronic paper, and then stored and controlled by the electronic papercontrol device 10. If a large capacity IC chip is mounted on eachelectronic paper 12, handwritten image or document information can bestored in the IC chip mounted on each electronic paper 12.

Although it depends on the structure of an electronic paper for use,usually, an electronic paper has characteristics such that, after dayshave elapsed since a document (image) was written on the electronicpaper, image quality of the written document (written image)deteriorates. For this reason, for each electronic paper on which adocument has been written, it is determined whether or not the number ofdays that have elapsed since the last date on which document was writtenon the electronic paper exceeds a predetermined value or it isdetermined whether or not the degree of deterioration of image qualityof the document exceeds a predetermined value by optically reading thedocument which is written on the electronic paper. If the determinationis affirmed, a refresh processing in which the document that has alreadybeen written on the electronic paper is rewritten on the same electronicpaper is carried out.

In an aspect in which it is determined whether or not the refreshprocessing is required based on the number of days which have elapsedsince a document was last written, the aspect can be structured suchthat date/time a document is written (“document writing date/time”,hereinafter) which is the date/time the document was finally written isrecorded on an electronic paper or a recording medium separated from theelectronic paper each time a document is written on an electronic paper,and the document writing date/time can be recognized by reading adocument writing date/time from the electronic paper or the recordingmedium. Further, if the document writing date/time is registered in thecontrol DB 44 in advance, the control center 38 can determine whether ornot the refresh processing is required, based on the number of dayssince a document was finally written on an electronic paper. If anelectronic paper that requires the refresh processing does exist, it ispossible to inform the electronic paper control device 10 of theexistence of the electronic paper.

More specifically, it is determined whether or not the refreshprocessing is required based on the degree of deterioration of imagequality of a document, which is written on an electronic paper asdescribed below.

Document information corresponding to the document which is written onthe electronic paper 12 that is supposed to a determination(hereinafter, “determination-object electronic paper”) is obtained fromthe control DB 44 of the control center 38. Based on the obtaineddocument information and the writing-condition information that iscontained in the reading control information from thedetermination-object electronic paper 12, a document image whichrepresents the document which has been displayed on the electronic paper12 is generated just after the document has been written on thedetermination-object electronic paper 12. Then, the determination-objectelectronic paper 12 (or a document, which is written thereon) isoptically read. Due to the determination whether or not a differencebetween a density (estimated value) of the document represented by thegenerated document image and the read density is more than apredetermined value (for example, determination whether or not a ratioof an area of a region whose optical density difference is about 0.01 ormore to an area of the entire document which is written on theelectronic paper 12 exceeds a predetermined value), it can be determinedwhether or not a degree of deterioration of image quality of a documentexceeds a predetermined value.

Due to the above-described determinations, if the refresh processing isdetermined to be required, the refresh processing in which the documentwhich has already been written on the electronic paper 12 which isdetermined to require the refresh processing is rewritten on the sameelectronic paper is carried out, whereby deterioration of image qualityof the document which has already been written on the electronic papercan be prevented.

1. An electronic paper reading device comprising: a delete controlcomponent for deleting a display of a first image from an electronicpaper which is filled out by hand in a state in which a first imagewhich has been recorded on the electronic paper in advance, is beingdisplayed; and a reading component for obtaining image data of a secondimage representing contents with which the electronic paper is filledout by hand, by optically reading the electronic paper from which thedisplay of the first image has been deleted by the delete controlcomponent.
 2. The device of claim 1, further comprising a controlcomponent which recognizes identification information for identifyingthe electronic paper which is filled out by hand, and which associatesthe obtained image data of the second image with the identificationinformation and manages the image data.
 3. The device of claim 2,further comprising a detection component for detecting a relationshipbetween orientation of the electronic paper or the first image, and thatof the second image, wherein, based on the relationship that is detectedby the detection component, the control component controls the imagedata of the second image to orient the first image and the second imagein the same direction when both the first image and the second image arerecorded on the electronic paper.
 4. An electronic paper reading devicecomprising: a reading component for optically reading an electronicpaper which is filled out by hand in a state in which a first imagewhich is recorded in advance on the electronic paper is being displayed,wherein the electronic paper is filled out by hand by using ink havingcharacteristics such that a reflectance of the ink is different fromthat of the electronic paper within a predetermined wavelength region inwhich a difference of at least one of a reflectance and a light emittingenergy between a portion on the electronic paper at which the firstimage is recorded and a portion on the electronic paper at which thefirst image is not recorded thereon is less than a predetermined value,and the reading component obtains image data of a second image thatrepresents contents with which the electronic paper is filled out byhand by optically reading the electronic paper by using a sensor whichis sensitive to the predetermined wavelength region.
 5. The device ofclaim 4, further comprising a control component which recognizesidentification information for identifying the electronic paper which isfilled out by hand, and which associates the obtained image data of thesecond image with the identification information and manages the imagedata.
 6. The device of claim 5, further comprising a detection componentfor detecting a relationship between orientation of the electronic paperor the first image, and that of the second image, wherein, based on therelationship that is detected by the detection component, the controlcomponent controls the image data of the second image to orient thefirst image and the second image in the same direction when both thefirst image and the second image are recorded on the electronic paper.7. An electronic paper reading system comprising: an electronic paperreading device; and a control device, wherein the electronic paperreading device and the control device are connected to each other via anetwork so as to be able to communicate with each other, the electronicpaper reading device including: a reading component for opticallyreading an electronic paper which is filled out by hand, in a state inwhich a first image which has been recorded on the electronic paper inadvance is displayed; a recognition component for recognizing the firstimage; and an extracting component for extracting image data of a secondimage that represents contents with which the electronic paper is filledout by hand, based on a recognizing result of the first image by therecognition component and a reading result due to the reading component,and wherein the control device recognizes identification information foridentifying the electronic paper which is filled out by hand, andassociates the obtained image data of the second image with theidentification information and manage the image data.